Methods and apparatus for applying tubular elastic members



Dec. 6, 1955 H. F. GATES METHODS AND APPARATUS FOR APPLYING TUBULAR ELASTIC MEMBERS Filed Oct. 1, 1951 Fig. 4

3nventor HARRY F. GATES Fig. 5

a M nr J a m Gttornegs METHODS AND APPARKTUSAEQ'R Arr-LYING TUBULAR nrasrrc Harry F. -Gates, Denver, Colo.,. asslgiior toThe Gates Rubber Company, Denver, Colo., a corporation of Colorado Application 'o'c'tobsr 1, 1 951, "serial No. mm

4 Claims. (Cl. 29-413) This invention relates to improvements in methods and apparatus for applying tubular elastic members to objects, and particularly to applying protector sleeves on drill pipe to prevent contact between the drill pipe and the drill casing surrounding same. Patent No. 2,435,868 to Boyd, et al., describes in detail the purpose of such protectors and the manner in which they have formerly been applied, together with a construction wherein a protector is disposed on a two-part sleeve and the protector permitted to collapse on the drill pipe when the parts of the sleeve are disengaged upon relative rotation. The present invention relates more particularly to the general class of methods and apparatus for applying protectors as exemplified by said patent.

One of the objects of the invention is to provide methods and apparatus for more readily applying protectors to drill pipes without the use of special tools.

Another object is to provide protector holding sleeves which permit collapse of the protectors onto the pipe by application of an impact, such as by a hammer, or other impact device.

Another object is to provide sleeves which automatically eject from the protector after application of an impact.

Further objects are to provide sleeves which either cl lapse or disintegrate in a position between the protector and pipe.

Still further objects, advantages, and salient features will become more apparent from the description to follow, the appended claims, and the accompanying drawing, in which:

Figure 1 is a vertical section through a portion of a well casing with a drill pipe disposed therein;

Figure 2 is a vertical section through one embodiment of the invention showing a protector holding sleeve, with the protector disposed thereon, in a position relative to the drill pipe, as it is being applied thereto;

Figures 3 to 5 are similar sections of other embodiments of the invention.

Referring in detail to the drawing, and particularly Figure 1, a conventional well casing disposed in the ground contains the conventional rotating drill pipe 11, this being formed in sections detachably connected together by enlarged threaded couplings 12.

A plurality of protectors 13, one of which is shown, are disposed on these sections at desired positions and prevent the sections from engaging the casing, as well understood in the art.

Referring to Figure 2, the protector, prior to its application to the drill pipe, is disposed under high circumferential tensional stress on a circular frangible sleeve 14, having a frusto-conical surface and a circular collar 16 at one end. The inside diameter of the sleeve exceeds,

the diameter of coupling 12 so that the assembly may be passed over the coupling and disposed at a desired point between the ends of a section of drill pipe. When the assembly is disposed in its desired position, collar 16 is struck with an impact tool which fractures the sleeve 2,725,621 Patented Dec. 6, I951.

tical and axial components of force to the sleeve which ejects the latter from the protector as it collapses onto the drill pipe to engage same. To localize the fracture line, 'cum'ferenti a'l weakening groove 17 may be provided. To aid the ejection of thcsleeve, while main in'i'n'g a small cone angle, a lubricant, such as grease, is applied to the frusto conical urface before the protector is applied thereto. After the sleeve has been ejected, it may be reih'dved over "the coupling, or alternatively, struck with an impact tool to effect its disintegration. The sleeve may be constructed of any suitable frangible material, such as brittle hard rubber, ceramics, glass, etc. The protector may be of any rubber-like or other elastic material, preferably having good abrasion resisting characteristics.

Figure 3 illustrates a variant of Figure 2 wherein the sleeve 14a is threaded at one end and a collar 16a, in the form of a threaded nut, engages the threads. This collar or nut is constructed of any frangible material with angularly spaced fracture grooves 17a so that an impact on the nut will break it into several pieces and permit the sleeve to be ejected. The sleeve in this embodiment is preferably constructed of metal or a strong plastic material which does not fracture and, hence, may be reloaded for reuse, the only wasted part of the sleeve unit then being the frangible nut.

The construction shown in Figure 4 is similar to Figures 2 and 3 except that the sleeve 14b is provided with opposed frusto-conical surfaces and the fracture groove 17b is disposed therebetween. A radially directed impact to protector 13 adjacent groove 17b effects breaking of the sleeve into two parts, the parts being ejected from the protector in opposite directions axially of the 'drill pipe.

In Figure 5, right circular sleeve is constructed of frangible material so that an impact to protector 13 disintegrates the sleeve. In this construction, at least a portion of the sleeve particles will usually remain between the outside of the drill pipe and the inner surface of the protector after the latter collapses on the former.

. Having described the invention, what is claimed as new is:

1. A device for applying elastic protectors onto pipes comprising a sleeve having a frusto-conical outer surface terminating at its smaller end in an integral outwardly extending portion forming a stop for holding an elastic protector stationary in extended position on the frustoconical surface, the sleeve having a fracture line of reduced cross sectional area at its juncture with said outwardly extending stop portion, said stop portion being separable from the sleeve by an impact blow fracturing the sleeve along the said fracture line.

2. The method of applying an annular elastic protector to a pipe comprising, the steps of radially expanding the protector and inserting thereinto a sleeve, said sleeve being in a frangible condition and capable of being shattered upon impact, passing said sleeve over said pipe end and locating said sleeve and protector at the desired location for said protector and finally fracturing said sleeve by an impact blow, the fracture extending around the entire surface of the sleeve and dividing said sleeve into at least two segments, whereby the resilient force of said protector expels said sleeve segments and said protector collapses about said pipe.

3. A device for use in placing protectors at the desired locations on drill pipes comprising, a frangible sleeve having a frusto-conical outer surface, the smaller end of the sleeve having an outwardly extending stop portion, the sleeve having a fracture line of reduced cross section adjacent the stop portion adapted to fracture when an impact blow is applied to the stop portion, and an annular elastic protector supported in expanded position on the outer surface of the sleeve and held from relative longitudinal movement thereon by said stop portion, whereby when said stop portion is separated from the sleeve by an impact blow the elastic protector will expel the sleeve and position itself above the drill pipe.

4. A device for applying an annular elastic protector to a drill pipe comprising, a sleeve capable of being fractured upon impact, the outer surface of said sleeve being frusto-conical, an annular elastic protector positioned on said sleeve in expanded condition, said sleeve and elastic protector being adapted to be passed over a drill pipe to be protected, a radially extending stop portion at the smaller end of the sleeve forming a stop for theprotector, whereby when the stop portion is removed by an impact blow of suflicient intensity to fracture the connection between it and the sleeve the protector will expel the sleeve and position itself on the drill pipe.

References Cited in the file of this patent UNITED STATES PATENTS Ruder Mar. 15, 1927 Sanders et a1. Dec. 8, 1931 McCoy Aug. 20, 1946 Boyd et al Feb. 10, 1948 Ballagh Sept. 19, 1950;

Hillberg Nov. 3, 1953 FOREIGN PATENTS Great Britain Sept. 22, 1944 

